It may be invalid.   I sent my husband to look and he said it was negative.   When I went back in to get ready for work, I saw the faint line.  I texted him and asked if the faint line was there when he checked and he said it was.  (He didn't know that means positive). But I'm not sure because a) it's a blue dye test, and b) I don't know if the timing was too late to actually look at it (past 10 min).   I will be retesting tomorrow with a different test